Dampened spring-operated vertically accumulating container storage and retrieval system

ABSTRACT

A vertically accumulating storage and retrieval apparatus has a first and second plurality of substantially vertically spaced shelf assemblies supported by support structure. Each of the shelf assemblies includes a shelf tray for receiving, storing, and discharging containers. Spring biasing structure is provided for urging the shelf to the receiving position. Dampening structure dampens the movement of the shelf between the upwardly tilted receiving position and the downwardly tilted discharge position. A transfer control and transfer control linkage are provided for retaining the shelf when a shelf of a next lower shelf assembly is not prepared to receive a container, and allowing the shelf to move to the discharge position under the weight of a container disposed on the shelf when the shelf of the next lower shelf assembly is prepared to receive a container. A method for storing and retrieving containers is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 12/315,837 filed Dec. 5, 2008, now U.S. Pat. No. 7,963,383,issued Jun. 21, 2011 which claims the priority of U.S. ProvisionalPatent Application No. 60/992,593, filed Dec. 5, 2007, which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates generally to automated storage and retrievalsystems, and is more specifically related to vertically accumulatingcontainer storage and retrieval systems.

BACKGROUND OF THE INVENTION

Vertically accumulating container storage and retrieval systems are knowin the art. Exemplary systems are shown in Stingel et al., U.S. Pat. No.6,729,836; Stingel et al, U.S. Pat. No. 7,200,465; and Stingel et al,U.S. Pat. No. 7,184,855; and Grace, U.S. Pat. No. 4,621,745. Thedisclosures of the patents are incorporated by reference. In suchsystems, a first plurality of substantially vertically spaced shelfassemblies is supported by support structure and a second plurality ofsubstantially vertically spaced shelf assemblies is supported by supportstructure. Each shelf assembly includes a shelf tray for receiving,storing, and discharging containers. The shelf trays of the firstplurality of shelf assemblies are substantially staggered verticallyrelative to the shelf trays of the second plurality of shelf assemblies,with the free ends of the trays of one plurality of shelf assembliesfacing the free ends of the trays of the other plurality of shelfassemblies. Each shelf tray is mounted to its respective verticalsupport for pivotal movement at least between an upwardly tiltedreceiving position and a downwardly tilted discharge position. Atransfer control is operatively connected to the shelf assembly and hasa lock position retaining the shelf tray when a shelf tray of a nextlower shelf assembly is not prepared to receive a container, and arelease position, allowing the shelf to move to the discharge positionunder the weight of a container disposed on the shelf tray when theshelf tray of the next lower shelf assembly is prepared to receive acontainer. Containers move downward through the vertical stacks of shelfassemblies from side-to-side in a substantially downward back and forthfashion until a container has reached the lowest open containerposition.

Biasing is provided to urge the shelf trays to the upwardly tiltedreceiving position. The biasing has been accomplished by gas cylinders.Gas cylinders are susceptible to degradation due to loss of gas, as wellas performance issues which are relative to the temperature of the gas.In a cold environment or during winter months, the performance of thegas cylinders can be markedly different from the performance of thecylinders during warmer months. Changes in gas cylinder performanceaffects the movement of containers through the towers and can result inunnecessary vibration or jarring of the containers. Replacement, repair,or adjustment of gas cylinders can be time consuming and expensive.

BRIEF DESCRIPTION OF THE DRAWINGS

There is shown in the drawings embodiments which are presentlypreferred, it being understood, however, that the invention can beembodied in other forms without departing from the spirit or essentialattributes thereof.

FIG. 1 (A-C) is a perspective view of a shelf assembly according to theinvention.

FIG. 2 (A-C) is an enlarged perspective view of areas A-C in FIG. 1.

FIG. 3 (A-C) is a perspective view of a shelf assembly according to theinvention in differing modes of operation, with a biasing spring removedto reveal features.

FIG. 4 (A-C) is an enlarged perspective view of areas A-C in FIG. 3.

FIG. 5 is a top plan view of a shelf assembly according to theinvention.

FIG. 6 is an enlarged view of area A in FIG. 5.

FIG. 7 is a front elevation of a shelf assembly according to theinvention with a biasing spring removed to reveal features.

FIG. 8 is an enlarged view of area B in FIG. 7.

FIG. 9 is a bottom plan view of a shelf assembly according to theinvention.

FIG. 10 is an enlarged bottom view of area C in FIG. 9.

FIG. 11 is a side elevation of a shelf assembly according to theinvention.

FIG. 12 is an enlarged view of area D in FIG. 11.

FIG. 13 is a side elevation of a shelf assembly, partially broken awayand partially in phantom, in a first mode of operation.

FIG. 14 is a side elevation, partially broken away and partially inphantom, of a shelf assembly in a second mode of operation.

FIG. 15 is a side elevation, partially broken away and partially inphantom, in a third mode of operation.

DETAILED DESCRIPTION OF THE INVENTION

There is shown in FIGS. 1-15 a container storage and retrieval system 20which comprises a plurality of shelf tray assemblies 24. Each shelf trayassembly 24 includes a shelf tray 28 that is pivotally mounted to asupport 32 about a pivot pin 36.

Spring 40 is provided to urge shelf 28 to the upwardly tilted positionshown in FIGS. 1C, 2C, 3C and 4C. Spring 40 can be a metal coil springas shown. Other spring types, including elastic polymeric bands andcords, or other forms of metal springs, such as leaf springs, canalternatively be utilized. It is also possible to provide the springelsewhere in the shelf tray assembly. For example, the spring could bepositioned at the rear of the shelf tray 28 and act to rotate the shelftray about the pivot pin 36. Such a spring could be a coil spring or aleaf spring. Other constructions are possible. The strength of thesprings can vary depending on the size and construction of the trays 28,and also upon the size and weight of containers that will be stored onthe trays. In one embodiment for smaller containers, the spring is about9.3 lbf/in, and for larger containers is about 12.6 lbf/in. In anotherembodiment the spring strength is between about 6 and about 17 lbf/in.

The spring 40 can be mounted between the support 32 and the tray 28 in avariety of ways. A spring seat 46 can be mounted to the supportstructure 32 in order to retain an upper end of the spring 40. Thebottom end of the spring 40 can be connected directly to the tray 28. Inthe embodiment shown, the bottom end of the spring 40 is connected to atray return cam 44 that is pivotally mounted to the support 32 about apivot pin 48. The tray return cam 44 can have an extension lever 65 forattaching to the spring. The tray return cam 44 has a cam ledge 52 foracting on a cam follower 56. The cam follower 56 can be mounted to theshelf tray 28, but in the embodiment shown is mounted to a transferlinkage bracket 58. The transfer linkage bracket 58 has a transferlinkage 62 which acts to permit lowering of a shelf tray only when thenext lower shelf tray is in the receiving position. Spring 40 therebyacts to lift the tray return cam 44 so as to urge the cam ledge 52against the cam follower 56. This will cause the shelf tray 28 to movefrom the downwardly tilted position (FIG. 1B) to the upwardly tiltedposition (FIG. 1C). The action of the spring 40 on the tray return cam44 and thereby the cam follower 56 creates a lever action which assistsin raising the tray 28 and allows for a weaker spring 40 than wouldotherwise be required. As is known in such systems, the shelf trayassemblies can be constructed so as to also provide a substantiallyhorizontal storage position (FIG. 1A).

The action of the spring 40 on the shelf tray 28 can cause vibrationsand jarring. Dampening structure can be provided to dampen the movementof the shelf tray 28 under the influence of the spring 40. Any suitabledampening structure can be provided. In the embodiment shown, abi-directional damper is provided in the form of a shock absorber suchas a fluid cylinder 60. Other dampening structure is possible, forexample, a torsion damper about or in the vicinity of the pivot pin 36,or a fluid bearing constructed to dampen movement of the tray. In someinstances, dampening structure may not be necessary, such as when thespring strength and container weight are such that jarring of the traywill not occur. The dampening cylinder 60 is connected between thesupport 32 and the tray return cam 44. Other connections of thedampening cylinder are possible. It is also possible to utilize twouni-directional dampening devices, connected so as to apply dampeningforces to the tray in opposing directions. As the tray 28 moves upwardunder the influence of the spring 40, the damper 60 will act on the trayreturn cam 44 against the action of the spring 40. Also, as the tray 28falls under the weight of the container, the bi-directional damper 60will act on the tray return cam 44 to reduce jarring and vibrations ofthe shelf tray 28.

A container arresting arm 70 can be provided to engage containers on theshelf tray 28. The container arresting arm 70 is operatively connectedto a fluid cylinder 74 and biasing spring 78 to dampen the motion of thecontainer arresting arm 70 as it is struck by a container moving throughthe tower and onto the shelf tray 28. Other dampening structure ispossible.

This invention can be embodied in other forms without departing from thespirit or essential attributes thereof and, accordingly, referenceshould be had to the following claims rather than the foregoingspecification as indicating the scope of the invention.

1. A vertically accumulating storage and retrieval apparatus comprising:a first plurality of substantially vertically spaced shelf assembliessupported by support structure; and a second plurality of substantiallyvertically spaced shelf assemblies supported by support structure, eachof said shelf assemblies including: a shelf tray for receiving, storing,and discharging containers, the shelf trays of the first plurality ofshelf assemblies being substantially staggered vertically relative tothe shelf trays of the second plurality of shelf assemblies, with freeends of the shelf trays of each plurality of shelf assemblies facing thefree ends of the other plurality of shelf assemblies, each shelf traybeing mounted to its respective vertical support for pivotal movementbetween an upwardly tilted receiving position and a downwardly tilteddischarge position; spring biasing structure for urging the shelf trayto the receiving position; and a transfer control operatively connectedto the shelf tray and having a lock position retaining the shelf traywhen a shelf tray of a next lower shelf assembly is not prepared toreceive a container, and a release position allowing the shelf tray tomove to the discharge position under the weight of a container disposedon said shelf tray when the shelf tray of the next lower shelf assemblyis prepared to receive a container.
 2. The vertically accumulatingstorage and retrieval apparatus of claim 1, further comprising dampeningstructure for dampening the movement of said shelf tray.
 3. Thevertically accumulating storage and retrieval apparatus of claim 2,wherein said dampening structure dampens the movement of said shelf trayto said upwardly tilted receiving position.
 4. The verticallyaccumulating storage and retrieval apparatus of claim 2, wherein saiddampening structure dampens the movement of said shelf tray to saiddownwardly tilted discharge position.
 5. The vertically accumulatingstorage and retrieval apparatus of claim 2, wherein said dampeningstructure is bi directional.
 6. The vertically accumulating storage andretrieval apparatus of claim 1, further comprising a transfer controllinkage operatively connected between the transfer control and the nextlower shelf assembly for transitioning the transfer control to therelease position when the next lower shelf tray is prepared to receive acontainer.
 7. The vertically accumulating storage and retrieval deviceof claim 2, wherein said dampening structure is a fluid cylinder.
 8. Thevertically accumulating storage and retrieval apparatus of claim 1,wherein said spring is a metal coil spring.
 9. The verticallyaccumulating storage and retrieval apparatus of claim 1, wherein saidspring is an elastic polymeric spring.
 10. The vertically accumulatingstorage and retrieval apparatus of claim 1, further comprising a trayreturn cam, said tray return cam being pivotally mounted to said supportstructure, and a cam follower, said cam follower being operativelyconnected to said shelf tray.
 11. The vertically accumulating storageand retrieval apparatus of claim 10, further comprising dampeningstructure, wherein said dampening structure is connected to said trayreturn cam, and extends from a bottom portion of said tray return cam tosaid support structure.
 12. The vertically accumulating storage andretrieval apparatus of claim 2, wherein said dampening structure isconnected to said shelf tray and to said support structure.
 13. A methodfor storing and retrieving containers, comprising the steps of:providing a vertically accumulating storage and retrieval apparatus,comprising a first plurality of substantially vertically spaced shelfassemblies supported by support structure and a second plurality ofsubstantially vertically spaced shelf assemblies supported by supportstructure, each of said shelf assemblies including a shelf tray forreceiving, storing, and discharging containers, the shelf trays of thefirst plurality of shelf assemblies being substantially staggeredvertically relative to the shelf trays of the second plurality of shelfassemblies, with free ends of the shelf trays of each plurality of shelfassemblies facing the free ends of the shelf trays of the otherplurality of shelf assemblies, each shelf tray being mounted to itsrespective vertical support for pivotal movement between an upwardlytilted receiving position and a downwardly tilted discharge position;moving a shelf tray to the receiving position with spring biasing;dampening the movement of said shelf tray between said upwardly tiltedreceiving position and said downwardly tilted discharge position;retaining the shelf tray when a shelf tray of a next lower shelfassembly is not prepared to receive a container, and allowing the shelftray to move to the discharge position under the weight of a containerdisposed on said shelf tray when the shelf tray of the next lower shelfassembly is prepared to receive a container.